Reproducibility of vibration perception threshold values in children and adolescents with type 1 diabetes mellitus and associated factors

Abstract

Aims: To define the reproducibility of vibration perception thresholds (VPTs) and the possible associated factors, as an early index of peripheral diabetic neuropathy (PDN) in type 1 diabetes mellitus (T1DM) children and adolescents.

Methods: A single examiner studied 118 T1DM subjects (aged 13.5±3.4 years) and 79 controls (aged 12.0±3.07 years). Glycaemic control was assessed with HbA1c levels. VPT was measured twice on upper and lower limbs, using a Biothesiometer. Concordance between the two VPT measurements was evaluated using the Cohen's Weighted Kappa statistic (Kappa=0.41-0.60→moderate concordance, Kappa=0.61-0.80→substantial concordance).

Results: T1DM children had significantly higher VPTs than controls at all sites (p=0.001), but with lower Kappa values (0.64-0.70). VPT values increased in parallel with HbA1c (a.<8%, b. 8-9.5%, c.>9.5%) and T1DM duration (a.<5 years, b.5.1-10, c.>10 years). However, Kappa values were lower in the groups with the poorest control (HbA1c>9.5%) (Kappa=0.54-0.76) or the longest T1DM duration (>10 years) (Kappa=0.49-0.71). Although VPTs increased with stature and male gender, no effect on VPT reproducibility was observed. However, obesity was associated with lower VPT values and poorer concordance.

Conclusions: These findings suggest that the reproducibility of VPTs is lower in the high-risk patients for early subclinical PDN development, who need a regular follow-up.

Keywords: Diabetic neuropathy; Reproducibility; Vibration sense.